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1 | /* |
2 | * CPiA video decoder. | |
3 | * Copyright (c) 2010 Hans de Goede <hdegoede@redhat.com> | |
4 | * | |
5 | * This decoder is based on the LGPL code available at | |
6 | * https://v4l4j.googlecode.com/svn/v4l4j/trunk/libvideo/libv4lconvert/cpia1.c | |
7 | * | |
8 | * This file is part of FFmpeg. | |
9 | * | |
10 | * FFmpeg is free software; you can redistribute it and/or | |
11 | * modify it under the terms of the GNU Lesser General Public | |
12 | * License as published by the Free Software Foundation; either | |
13 | * version 2.1 of the License, or (at your option) any later version. | |
14 | * | |
15 | * FFmpeg is distributed in the hope that it will be useful, | |
16 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
17 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
18 | * Lesser General Public License for more details. | |
19 | * | |
20 | * You should have received a copy of the GNU Lesser General Public | |
21 | * License along with FFmpeg; if not, write to the Free Software | |
22 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
23 | */ | |
24 | ||
25 | #include "avcodec.h" | |
26 | #include "get_bits.h" | |
27 | #include "internal.h" | |
28 | ||
29 | ||
30 | #define FRAME_HEADER_SIZE 64 | |
31 | #define MAGIC_0 0x19 /**< First header byte */ | |
32 | #define MAGIC_1 0x68 /**< Second header byte */ | |
33 | #define SUBSAMPLE_420 0 | |
34 | #define SUBSAMPLE_422 1 | |
35 | #define YUVORDER_YUYV 0 | |
36 | #define YUVORDER_UYVY 1 | |
37 | #define NOT_COMPRESSED 0 | |
38 | #define COMPRESSED 1 | |
39 | #define NO_DECIMATION 0 | |
40 | #define DECIMATION_ENAB 1 | |
41 | #define EOL 0xfd /**< End Of Line marker */ | |
42 | #define EOI 0xff /**< End Of Image marker */ | |
43 | ||
44 | ||
45 | typedef struct { | |
46 | AVFrame *frame; | |
47 | } CpiaContext; | |
48 | ||
49 | ||
50 | static int cpia_decode_frame(AVCodecContext *avctx, | |
51 | void *data, int *got_frame, AVPacket* avpkt) | |
52 | { | |
53 | CpiaContext* const cpia = avctx->priv_data; | |
54 | int i,j,ret; | |
55 | ||
56 | uint8_t* const header = avpkt->data; | |
57 | uint8_t* src; | |
58 | int src_size; | |
59 | uint16_t linelength; | |
60 | uint8_t skip; | |
61 | ||
62 | AVFrame *frame = cpia->frame; | |
63 | uint8_t *y, *u, *v, *y_end, *u_end, *v_end; | |
64 | ||
65 | // Check header | |
66 | if ( avpkt->size < FRAME_HEADER_SIZE | |
67 | || header[0] != MAGIC_0 || header[1] != MAGIC_1 | |
68 | || (header[17] != SUBSAMPLE_420 && header[17] != SUBSAMPLE_422) | |
69 | || (header[18] != YUVORDER_YUYV && header[18] != YUVORDER_UYVY) | |
70 | || (header[28] != NOT_COMPRESSED && header[28] != COMPRESSED) | |
71 | || (header[29] != NO_DECIMATION && header[29] != DECIMATION_ENAB) | |
72 | ) { | |
73 | av_log(avctx, AV_LOG_ERROR, "Invalid header!\n"); | |
74 | return AVERROR_INVALIDDATA; | |
75 | } | |
76 | ||
77 | // currently unsupported properties | |
78 | if (header[17] == SUBSAMPLE_422) { | |
79 | avpriv_report_missing_feature(avctx, "4:2:2 subsampling"); | |
80 | return AVERROR_PATCHWELCOME; | |
81 | } | |
82 | if (header[18] == YUVORDER_UYVY) { | |
83 | avpriv_report_missing_feature(avctx, "YUV byte order UYVY"); | |
84 | return AVERROR_PATCHWELCOME; | |
85 | } | |
86 | if (header[29] == DECIMATION_ENAB) { | |
87 | avpriv_report_missing_feature(avctx, "Decimation"); | |
88 | return AVERROR_PATCHWELCOME; | |
89 | } | |
90 | ||
91 | src = header + FRAME_HEADER_SIZE; | |
92 | src_size = avpkt->size - FRAME_HEADER_SIZE; | |
93 | ||
94 | if (header[28] == NOT_COMPRESSED) { | |
95 | frame->pict_type = AV_PICTURE_TYPE_I; | |
96 | frame->key_frame = 1; | |
97 | } else { | |
98 | frame->pict_type = AV_PICTURE_TYPE_P; | |
99 | frame->key_frame = 0; | |
100 | } | |
101 | ||
102 | // Get buffer filled with previous frame | |
103 | if ((ret = ff_reget_buffer(avctx, frame)) < 0) | |
104 | return ret; | |
105 | ||
106 | ||
107 | for ( i = 0; | |
108 | i < frame->height; | |
109 | i++, src += linelength, src_size -= linelength | |
110 | ) { | |
111 | // Read line length, two byte little endian | |
112 | linelength = AV_RL16(src); | |
113 | src += 2; | |
114 | ||
115 | if (src_size < linelength) { | |
116 | av_frame_set_decode_error_flags(frame, FF_DECODE_ERROR_INVALID_BITSTREAM); | |
117 | av_log(avctx, AV_LOG_WARNING, "Frame ended unexpectedly!\n"); | |
118 | break; | |
119 | } | |
120 | if (src[linelength - 1] != EOL) { | |
121 | av_frame_set_decode_error_flags(frame, FF_DECODE_ERROR_INVALID_BITSTREAM); | |
122 | av_log(avctx, AV_LOG_WARNING, "Wrong line length %d or line not terminated properly (found 0x%02x)!\n", linelength, src[linelength - 1]); | |
123 | break; | |
124 | } | |
125 | ||
126 | /* Update the data pointers. Y data is on every line. | |
127 | * U and V data on every second line | |
128 | */ | |
129 | y = &frame->data[0][i * frame->linesize[0]]; | |
130 | u = &frame->data[1][(i >> 1) * frame->linesize[1]]; | |
131 | v = &frame->data[2][(i >> 1) * frame->linesize[2]]; | |
132 | y_end = y + frame->linesize[0] - 1; | |
133 | u_end = u + frame->linesize[1] - 1; | |
134 | v_end = v + frame->linesize[2] - 1; | |
135 | ||
136 | if ((i & 1) && header[17] == SUBSAMPLE_420) { | |
137 | /* We are on a odd line and 420 subsample is used. | |
138 | * On this line only Y values are specified, one per pixel. | |
139 | */ | |
140 | for (j = 0; j < linelength - 1; j++) { | |
141 | if (y > y_end) { | |
142 | av_frame_set_decode_error_flags(frame, FF_DECODE_ERROR_INVALID_BITSTREAM); | |
143 | av_log(avctx, AV_LOG_WARNING, "Decoded data exceeded linesize!\n"); | |
144 | break; | |
145 | } | |
146 | if ((src[j] & 1) && header[28] == COMPRESSED) { | |
147 | /* It seems that odd lines are always uncompressed, but | |
148 | * we do it according to specification anyways. | |
149 | */ | |
150 | skip = src[j] >> 1; | |
151 | y += skip; | |
152 | } else { | |
153 | *(y++) = src[j]; | |
154 | } | |
155 | } | |
156 | } else if (header[17] == SUBSAMPLE_420) { | |
157 | /* We are on an even line and 420 subsample is used. | |
158 | * On this line each pair of pixels is described by four bytes. | |
159 | */ | |
160 | for (j = 0; j < linelength - 4; ) { | |
161 | if (y + 1 > y_end || u > u_end || v > v_end) { | |
162 | av_frame_set_decode_error_flags(frame, FF_DECODE_ERROR_INVALID_BITSTREAM); | |
163 | av_log(avctx, AV_LOG_WARNING, "Decoded data exceeded linesize!\n"); | |
164 | break; | |
165 | } | |
166 | if ((src[j] & 1) && header[28] == COMPRESSED) { | |
167 | // Skip amount of pixels and move forward one byte | |
168 | skip = src[j] >> 1; | |
169 | y += skip; | |
170 | u += skip >> 1; | |
171 | v += skip >> 1; | |
172 | j++; | |
173 | } else { | |
174 | // Set image data as specified and move forward 4 bytes | |
175 | *(y++) = src[j]; | |
176 | *(u++) = src[j+1]; | |
177 | *(y++) = src[j+2]; | |
178 | *(v++) = src[j+3]; | |
179 | j += 4; | |
180 | } | |
181 | } | |
182 | } | |
183 | } | |
184 | ||
185 | *got_frame = 1; | |
186 | if ((ret = av_frame_ref(data, cpia->frame)) < 0) | |
187 | return ret; | |
188 | ||
189 | return avpkt->size; | |
190 | } | |
191 | ||
192 | static av_cold int cpia_decode_init(AVCodecContext *avctx) | |
193 | { | |
194 | CpiaContext *s = avctx->priv_data; | |
195 | ||
196 | // output pixel format | |
197 | avctx->pix_fmt = AV_PIX_FMT_YUV420P; | |
198 | ||
199 | /* The default timebase set by the v4l2 demuxer leads to probing which is buggy. | |
200 | * Set some reasonable time_base to skip this. | |
201 | */ | |
202 | if (avctx->time_base.num == 1 && avctx->time_base.den == 1000000) { | |
203 | avctx->time_base.num = 1; | |
204 | avctx->time_base.den = 60; | |
205 | } | |
206 | ||
207 | s->frame = av_frame_alloc(); | |
208 | if (!s->frame) | |
209 | return AVERROR(ENOMEM); | |
210 | ||
211 | return 0; | |
212 | } | |
213 | ||
214 | static av_cold int cpia_decode_end(AVCodecContext *avctx) | |
215 | { | |
216 | CpiaContext *s = avctx->priv_data; | |
217 | ||
218 | av_frame_free(&s->frame); | |
219 | ||
220 | return 0; | |
221 | } | |
222 | ||
223 | AVCodec ff_cpia_decoder = { | |
224 | .name = "cpia", | |
225 | .long_name = NULL_IF_CONFIG_SMALL("CPiA video format"), | |
226 | .type = AVMEDIA_TYPE_VIDEO, | |
227 | .id = AV_CODEC_ID_CPIA, | |
228 | .priv_data_size = sizeof(CpiaContext), | |
229 | .init = cpia_decode_init, | |
230 | .close = cpia_decode_end, | |
231 | .decode = cpia_decode_frame, | |
232 | .capabilities = CODEC_CAP_DR1, | |
233 | }; |